There are around 96 left, all in captivity.
Edit: Last year due to the Lion man there is 100
1608
100
White tigers are only a rare color phase of the Bengal tiger. As of today, there are not any white tigers among the wild population.
1524 on 10/10/2008
Several hundred, all in captivity.
Expedition Great White - 2010 Tiger Escape 3-3 was released on: USA: 21 April 2012
My Life Is a Zoo - 2010 White Tiger Trouble 1-3 was released on: USA: 31 January 2011
The rare mutation of the tiger that is white is a Bengal tiger, not a Siberian. None have been seen among the wild Bengal population in years.
There is only about 200 worldwide. They are a mutation, there has never been a documented wild birth of a white tiger. All white tigers have been bred and raised from the same white tiger found in the 1950's, all inbred to keep the white gene alive.
The white tiger started from humans breeding tigers in captivity. To make the tiger thrive they would have to establish a small population of white tigers to release in the wild because a tiger with and orange coloring will not mate with a white tiger.
147,600 was the white population in 2010.
The white Bengal tiger's name is Shikira.